1. Field of the Invention
This invention relates generally to apparatus for extinguishing flames and relates particularly to a fire fighting system including one or more remotely controlled nozzles mounted on an aerial ladder of a fire truck.
2. Description of the Prior Art
Heretofore, fire fighting vehicles of the so-called "Hook and Ladder" type trucks have been provided with aerial ladders which were pivotally mounted on a swivel base and were adapted to be raised and lowered, extended and retracted, and swung about a vertical axis from a control pedestal on the base which was selectively operated by a fireman. Ordinarily, one or more additional firemen would climb the ladder with hoses to direct water under pressure onto the fire. By twisting a portion of the nozzle, or by operating a mechanical linkage, the fireman could adjust the intensity of the water being discharged from a steady stream to a fog. However, the amount of water being discharged, calculated in water pressure and gallons per minute, was limited by the physical ability of the fireman to control the nozzle. Since a fireman on an aerial ladder normally could not control the nozzle at pressures in excess of 60 to 80 p.s.i.g., the water could not be projected to great distances and, accordingly, it was necessary to locate the ladder close to the fire which increased the danger to the fireman.
To decrease the fireman's peril, as well as to increase the pressure and quantity of water passing through the nozzle, a manually controlled swivel type nozzle has been mounted on the end of the ladder; however, controlling the direction of the nozzle has been fatiguing to the fireman so that it was necessary to alternate firemen frequently. Also, the presence of a fireman on the ladder while the ladder was being extended and retracted has been dangerous since many fireman have been injured including by having toes and other portions of their bodies multilated by the moving sections of the ladder.
Some efforts have been made to provide a nozzle on the end of an aerial ladder and to provide apparatus for controlling the nozzle from a remote location. However, most of these structures have included chain and sprocket or rack and pinion connections between the nozzle control mechanism and the power plant for moving the same. These structures have not been satisfactory since they have required excessive power so that in many cases it has been necessary to provide a portable generator just to supply electrical energy to the nozzle operating apparatus. Also, since the nozzles have been mounted on the end of the ladder, they have been subjected to severe vibration and shaking particularly while the fire truck was speeding to a fire or while returning to the station. The malfunction of the remotely controlled nozzles has been so prevalent that many ladder companies have removed the nozzles from the ladder as long as the truck was moving and have installed the nozzles after the truck arrived at the fire. Obviously this has delayed the fighting of the fire during the crucial first few minutes after the equipment arrived at the scene of the fire. Some examples of the prior art are embodied in the following U.S. Pat. Nos.: 1,835,132 -- Anania; 2,593,921 -- Robinson; 2,698,664 -- Freeman; 3,010,519 -- Gillespie; 3,599,722 -- Davidson; 3,762,478 -- Cummins; and 3,770,062 -- Riggs.